aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/media/common/ir-functions.c
blob: bb2a027b94837d40740503ad50a94dbb71dc2b74 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
/*
 *
 * some common structs and functions to handle infrared remotes via
 * input layer ...
 *
 * (c) 2003 Gerd Knorr <kraxel@bytesex.org> [SuSE Labs]
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <linux/module.h>
#include <linux/string.h>
#include <linux/jiffies.h>
#include <media/ir-common.h>

/* -------------------------------------------------------------------------- */

MODULE_AUTHOR("Gerd Knorr <kraxel@bytesex.org> [SuSE Labs]");
MODULE_LICENSE("GPL");

static int repeat = 1;
module_param(repeat, int, 0444);
MODULE_PARM_DESC(repeat,"auto-repeat for IR keys (default: on)");

static int debug = 0;    /* debug level (0,1,2) */
module_param(debug, int, 0644);

#define dprintk(level, fmt, arg...)	if (debug >= level) \
	printk(KERN_DEBUG fmt , ## arg)

/* -------------------------------------------------------------------------- */

static void ir_input_key_event(struct input_dev *dev, struct ir_input_state *ir)
{
	if (KEY_RESERVED == ir->keycode) {
		printk(KERN_INFO "%s: unknown key: key=0x%02x raw=0x%02x down=%d\n",
		       dev->name,ir->ir_key,ir->ir_raw,ir->keypressed);
		return;
	}
	dprintk(1,"%s: key event code=%d down=%d\n",
		dev->name,ir->keycode,ir->keypressed);
	input_report_key(dev,ir->keycode,ir->keypressed);
	input_sync(dev);
}

/* -------------------------------------------------------------------------- */

void ir_input_init(struct input_dev *dev, struct ir_input_state *ir,
		   int ir_type, IR_KEYTAB_TYPE *ir_codes)
{
	int i;

	ir->ir_type = ir_type;
	if (ir_codes)
		memcpy(ir->ir_codes, ir_codes, sizeof(ir->ir_codes));


	dev->keycode     = ir->ir_codes;
	dev->keycodesize = sizeof(IR_KEYTAB_TYPE);
	dev->keycodemax  = IR_KEYTAB_SIZE;
	for (i = 0; i < IR_KEYTAB_SIZE; i++)
		set_bit(ir->ir_codes[i], dev->keybit);
	clear_bit(0, dev->keybit);

	set_bit(EV_KEY, dev->evbit);
	if (repeat)
		set_bit(EV_REP, dev->evbit);
}

void ir_input_nokey(struct input_dev *dev, struct ir_input_state *ir)
{
	if (ir->keypressed) {
		ir->keypressed = 0;
		ir_input_key_event(dev,ir);
	}
}

void ir_input_keydown(struct input_dev *dev, struct ir_input_state *ir,
		      u32 ir_key, u32 ir_raw)
{
	u32 keycode = IR_KEYCODE(ir->ir_codes, ir_key);

	if (ir->keypressed && ir->keycode != keycode) {
		ir->keypressed = 0;
		ir_input_key_event(dev,ir);
	}
	if (!ir->keypressed) {
		ir->ir_key  = ir_key;
		ir->ir_raw  = ir_raw;
		ir->keycode = keycode;
		ir->keypressed = 1;
		ir_input_key_event(dev,ir);
	}
}

/* -------------------------------------------------------------------------- */
/* extract mask bits out of data and pack them into the result */
u32 ir_extract_bits(u32 data, u32 mask)
{
	u32 vbit = 1, value = 0;

	do {
	    if (mask&1) {
		if (data&1)
			value |= vbit;
		vbit<<=1;
	    }
	    data>>=1;
	} while (mask>>=1);

	return value;
}

static int inline getbit(u32 *samples, int bit)
{
	return (samples[bit/32] & (1 << (31-(bit%32)))) ? 1 : 0;
}

/* sump raw samples for visual debugging ;) */
int ir_dump_samples(u32 *samples, int count)
{
	int i, bit, start;

	printk(KERN_DEBUG "ir samples: ");
	start = 0;
	for (i = 0; i < count * 32; i++) {
		bit = getbit(samples,i);
		if (bit)
			start = 1;
		if (0 == start)
			continue;
		printk("%s", bit ? "#" : "_");
	}
	printk("\n");
	return 0;
}

/* decode raw samples, pulse distance coding used by NEC remotes */
int ir_decode_pulsedistance(u32 *samples, int count, int low, int high)
{
	int i,last,bit,len;
	u32 curBit;
	u32 value;

	/* find start burst */
	for (i = len = 0; i < count * 32; i++) {
		bit = getbit(samples,i);
		if (bit) {
			len++;
		} else {
			if (len >= 29)
				break;
			len = 0;
		}
	}

	/* start burst to short */
	if (len < 29)
		return 0xffffffff;

	/* find start silence */
	for (len = 0; i < count * 32; i++) {
		bit = getbit(samples,i);
		if (bit) {
			break;
		} else {
			len++;
		}
	}

	/* silence to short */
	if (len < 7)
		return 0xffffffff;

	/* go decoding */
	len   = 0;
	last = 1;
	value = 0; curBit = 1;
	for (; i < count * 32; i++) {
		bit  = getbit(samples,i);
		if (last) {
			if(bit) {
				continue;
			} else {
				len = 1;
			}
		} else {
			if (bit) {
				if (len > (low + high) /2)
					value |= curBit;
				curBit <<= 1;
				if (curBit == 1)
					break;
			} else {
				len++;
			}
		}
		last = bit;
	}

	return value;
}

/* decode raw samples, biphase coding, used by rc5 for example */
int ir_decode_biphase(u32 *samples, int count, int low, int high)
{
	int i,last,bit,len,flips;
	u32 value;

	/* find start bit (1) */
	for (i = 0; i < 32; i++) {
		bit = getbit(samples,i);
		if (bit)
			break;
	}

	/* go decoding */
	len   = 0;
	flips = 0;
	value = 1;
	for (; i < count * 32; i++) {
		if (len > high)
			break;
		if (flips > 1)
			break;
		last = bit;
		bit  = getbit(samples,i);
		if (last == bit) {
			len++;
			continue;
		}
		if (len < low) {
			len++;
			flips++;
			continue;
		}
		value <<= 1;
		value |= bit;
		flips = 0;
		len   = 1;
	}
	return value;
}

/* RC5 decoding stuff, moved from bttv-input.c to share it with
 * saa7134 */

/* decode raw bit pattern to RC5 code */
static u32 ir_rc5_decode(unsigned int code)
{
	unsigned int org_code = code;
	unsigned int pair;
	unsigned int rc5 = 0;
	int i;

	for (i = 0; i < 14; ++i) {
		pair = code & 0x3;
		code >>= 2;

		rc5 <<= 1;
		switch (pair) {
		case 0:
		case 2:
			break;
		case 1:
			rc5 |= 1;
			break;
		case 3:
			dprintk(1, "ir-common: ir_rc5_decode(%x) bad code\n", org_code);
			return 0;
		}
	}
	dprintk(1, "ir-common: code=%x, rc5=%x, start=%x, toggle=%x, address=%x, "
		"instr=%x\n", rc5, org_code, RC5_START(rc5),
		RC5_TOGGLE(rc5), RC5_ADDR(rc5), RC5_INSTR(rc5));
	return rc5;
}

void ir_rc5_timer_end(unsigned long data)
{
	struct card_ir *ir = (struct card_ir *)data;
	struct timeval tv;
	unsigned long current_jiffies, timeout;
	u32 gap;
	u32 rc5 = 0;

	/* get time */
	current_jiffies = jiffies;
	do_gettimeofday(&tv);

	/* avoid overflow with gap >1s */
	if (tv.tv_sec - ir->base_time.tv_sec > 1) {
		gap = 200000;
	} else {
		gap = 1000000 * (tv.tv_sec - ir->base_time.tv_sec) +
		    tv.tv_usec - ir->base_time.tv_usec;
	}

	/* signal we're ready to start a new code */
	ir->active = 0;

	/* Allow some timer jitter (RC5 is ~24ms anyway so this is ok) */
	if (gap < 28000) {
		dprintk(1, "ir-common: spurious timer_end\n");
		return;
	}

	if (ir->last_bit < 20) {
		/* ignore spurious codes (caused by light/other remotes) */
		dprintk(1, "ir-common: short code: %x\n", ir->code);
	} else {
		ir->code = (ir->code << ir->shift_by) | 1;
		rc5 = ir_rc5_decode(ir->code);

		/* two start bits? */
		if (RC5_START(rc5) != ir->start) {
			dprintk(1, "ir-common: rc5 start bits invalid: %u\n", RC5_START(rc5));

			/* right address? */
		} else if (RC5_ADDR(rc5) == ir->addr) {
			u32 toggle = RC5_TOGGLE(rc5);
			u32 instr = RC5_INSTR(rc5);

			/* Good code, decide if repeat/repress */
			if (toggle != RC5_TOGGLE(ir->last_rc5) ||
			    instr != RC5_INSTR(ir->last_rc5)) {
				dprintk(1, "ir-common: instruction %x, toggle %x\n", instr,
					toggle);
				ir_input_nokey(ir->dev, &ir->ir);
				ir_input_keydown(ir->dev, &ir->ir, instr,
						 instr);
			}

			/* Set/reset key-up timer */
			timeout = current_jiffies +
				  msecs_to_jiffies(ir->rc5_key_timeout);
			mod_timer(&ir->timer_keyup, timeout);

			/* Save code for repeat test */
			ir->last_rc5 = rc5;
		}
	}
}

void ir_rc5_timer_keyup(unsigned long data)
{
	struct card_ir *ir = (struct card_ir *)data;

	dprintk(1, "ir-common: key released\n");
	ir_input_nokey(ir->dev, &ir->ir);
}

EXPORT_SYMBOL_GPL(ir_input_init);
EXPORT_SYMBOL_GPL(ir_input_nokey);
EXPORT_SYMBOL_GPL(ir_input_keydown);

EXPORT_SYMBOL_GPL(ir_extract_bits);
EXPORT_SYMBOL_GPL(ir_dump_samples);
EXPORT_SYMBOL_GPL(ir_decode_biphase);
EXPORT_SYMBOL_GPL(ir_decode_pulsedistance);

EXPORT_SYMBOL_GPL(ir_rc5_timer_end);
EXPORT_SYMBOL_GPL(ir_rc5_timer_keyup);

/*
 * Local variables:
 * c-basic-offset: 8
 * End:
 */